Various equipment for absorbing vibrational energy such as vibration isolators, vibration dampers or seismic isolators have recently been spread rapidly. Further, rubber compositions exhibiting a damping power (absorbing power) against vibrational energy are used in such equipment.
As means for imparting excellent damping characteristics to a rubber material, i.e., obtaining a rubber composition having excellent damping characteristics, it has been a common practice to add a large amount of carbon black or a petroleum resin to a rubber.
However, the addition of a large amount of carbon black had disadvantages in that the resulting composition was poor in processability in refining and that the resulting seismic isolator was poor in shear failure characteristics, though the resulting composition exhibited an enhanced damping capacity (i.e., an enhanced hysteresis loss). On the other hand, the addition of a large amount of a petroleum resin had a disadvantage in that the resulting rubber composition exhibited lowered creep characteristics and was poor in long-term endurance, though the composition was improved in damping characteristics.